Neuroblastoma Screening (PDQ®): Screening - Health Professional Information [NCI] - Evidence of Benefit
A study of mortality trends before and after the national mass screening program in Japan for neuroblastoma analyzed age-specific mortality rates from 1980 through 2006. Screening began in the mid-1980s and was halted in 2003. Mortality rates were either stable through the entire period for age groups 5 years to 9 years and 10 years to 14 years, or were declining before the initiation of screening and continued to do so through 2006 for age groups less than 1 year and 1 year to 4 years. Because the most recent year of death analyzed was 2006, any increase in age-specific mortality associated with the cessation of mass screening in 2003 would have been expected to occur among children aged less than 1 year or 1 year to 4 years. No such increase was observed. This is the first postscreening analysis to provide evidence that screening had no impact on mortality rates and that stopping screening had no adverse effect.
A study compared neuroblastoma incidence and mortality rates in Japan in three cohorts: children born before screening between 1980 and 1983, and those born during screening between 1986 and 1989, and between 1990 and 1998. Cumulative incidence was higher in the screened cohorts (21.56–29.80 cases per 100,000 births) compared with the prescreening cohort (11.56 cases). Cumulative mortality was lower in the screened cohorts compared with the prescreening cohort (3.90–2.83 vs. 5.38 deaths per 100,000 births). The impact of changes in treatment on these rates is unclear.
The Quebec Neuroblastoma Screening Project compared neuroblastoma incidence and mortality in a 5-year birth cohort (n = 476,603) from Quebec (where urinary screening was offered at 3 weeks and 6 months [overall compliance, 92%]) to various North American birth cohorts in which no screening took place. In this study, the incidence of early-stage disease in children younger than 1 year in the screened population more than doubled that expected, while in the control population, it approximated that expected (standardized incidence ratio, 3.03; 95% confidence interval [CI], 2.30–3.86) in Quebec versus 0.82 in Minnesota (95% CI, 0.41–1.38) and Ontario (95% CI, 0.53–1.17). The incidence of advanced-stage disease (stage III and stage IV) in older children in Quebec showed a statistically nonsignificant increase over that which would have been expected (standard incidence ratio, 1.52; 95% CI, 0.95–2.23). After approximately 8 years of follow-up (range 6–11 years) the neuroblastoma death rate in the screened population was not significantly different from rates in unscreened populations (standardized mortality ratio, 1.11 [95% CI, 0.64–1.92] for the Quebec cohort compared with Ontario children). Similar findings were observed in the German neuroblastoma study. Although final mortality rates are expected in 2008, an interim analysis shows that the death rate from neuroblastoma is similar in screened and control populations (1.6 vs. 1.9 deaths per 100,000 children). A study in Austria yielded a similar conclusion, though screening was performed at age 7 to 12 months. In the screening cohort, neuroblastoma incidence was statistically significantly higher than in children who were not screened (18.2 vs. 11.2 per 100,000 births), while mortality was not statistically significantly different (0.96 vs. 1.57 per 100,000 births).